RE: Bending at the waist? Contorted?
It's all in the anchor point Jeff, remember, you can take the peep out of the equation as well as long as the anchor point is constant. It's the golden triangle of anchor, eye and sight pin. Change the anchor, you change POI.
Take my buddy Nate and I, we're both seasoned shooters right? I take his bow, his 30 yard pin is dead on for me at 20 yards even though I align his peep with his sight housing. He has to hold my 20 low. Even though we center the peep with the sight housing, we anchor differently.